Apparatus for extruding matter



Jan. 19, 1937.

J. WELLS APPARATUS FOR EXTRUDING MATTER Filed Jan. 10, 1935 M th/70R J W15 A Z. 5

" #awm AZTORMSY Patented Jan. ,19, 1937 UNITED STATES PATENT OFFICE mam APPARATUS ma ax-riwnmo MATTER Application January 10, 1935, Serial No. 1,123 1 Claim. (01. 207-16) This inventionrelates to apparatus for ex-, tr'uding matter, and more particularly to improvements in cable sheath extruding apparatus.

5 Although not limited thereto, the present in- :Vention is particularly applicable. to cable sheath extruding presses of the intermittent extruding type, wherein the extruding chamber or press cylinder is filled with a charge of molten metal,

such as lead, which is first allowed to cool to an extruding temperature and is 'then extruded through the die into the form required, for example, cable sheath. When the lead-in the press cylinder is exhausted, or nearly so, the

5 extruding plunger is withdrawn and the cylinder is refilled with a fresh charge of molten.

lead and after the fresh charge is allowed to" cool to the proper temperature, the extruding operation is resumed. This cycle of operaticns is repeated until the entire length of cable is sheathed. i

- At the end of each extruding cycle, the small portion of the lead charge remaining in the bottom of the cylinder is in a substantially solid conditionrand, therefore, unless it is substantially free of dross or other impurities, it does not unite satisfactorily with the fresh charge of molten lead. It has been found, how- .ever, that a satisfactory union between the 3 lead of successive charges is obtained if, before refilling the press cylinder with a fresh charge of molten lead,' the upper surface of the residual portion of the preceding charge is remelted to an appreciable depth to insure that any- 35 dross or other impurities that may be contained 7 therein are displaced by the fresh charge and riseto the top surface thereof.

An object of the present invention is to provide, in an extruding apparatus of .the above 40 type, practical and efllcient means for remelting the residual portion of the metal in the extruding chamber before refilling the chamber with a fresh charge of molten metal.

In accordance" with the above object, one 45 embodiment of-the invention, as applied to an extruding press of the above mentioned type,

comprises means for heating the extruding plungerat or near the end of each extruding cycle so'tha't the residual portion of the metal 50 remaining in the press cylinder is remelted before the plunger is withdrawn to refill the cylinder with a fresh charge of molten metal. Specifically, this means preferably comprises one or more electrical heating elements mount- 55 ed within a removable end portion of the exaround the cable passing therethrough.

truding plunger and adapted to be connected at the proper time 'with a suitable electrical power supply.

In the accompanying drawing, the invention is disclosed, for example, as applied to a cable 5 sheath extruding press of the intermittent extruding type comprising the usual press cylin-- 'der l0 and die block ll carried by a hydraulic vpassed. The ram I2 is adaptedto be raised to elevate the cylinder ID to a position wherein 5 a fixed piston or extruding plunger l5 enters the cylinder, after which continued upward movement of thelcylinder causes the plunger IE to press the matter, such as lead, contained in the cylinder through the extruding die and 20 In accordance with a feature of the premntinv'ention, the extruding plunger l5, comprises a removable end portion HS in the form of a plug which is threaded to the body or shankyp'ortion 25 of the plunger. Suitably mounted within this removable plug is an electrical heating unit l8. As shown in the drawing, the heating unit l8 may consist of electrical resistance elements 20 mounted within a suitable casing 21 adapted to be cast within the plug I6. Terminal members 22 connected to the resistance elements 20 project upwardly through the plug it for connection with electrical conductors 23 which are adapted to be connected with a suitable electrical power supply (not shown).

The extruding plunger I5 is provided with a longitudinal bore 24 through which the conductors 23 are threaded for connection with the heating unit i8. The conductors 23 enter the 40 bore 24 through a radial bore 25 in the lupr kr end portion of the plunger, which portion does not at any time enter the press cylinder.

' The operation of the apparatus is as follows:

' With the press cylinder in its lowermost position, it is filled with molten lead from a suitable melting kettle (not shown). After a. short time is allowed for the charge to solidify, the press cylinder is elevated by the ram l2 causing the plunger ii to press the lead through the die and around the cable passing therethrough, When the press cylinder reaches its uppermost position the lead charge is extruded down to. the point A,

f leaving a portion or slu'g 26 of solidified lead in the bottom of the cylinder and in the extruding die. At or near the end 0! the extruding cycle and before lowering the cylinder to withdraw the extruding plunger, the electrical heating unit I8 is energized toheat the lower end of the plunger sumciently to remelt the upper surface of the residual slug 26 to an appreciable depth so as to insure that any dross or other impurities that maybe contained therein will rise to the top of the succeeding fresh charge. The heating unit I! is then disconnected from its energizing current, after which the press cylinder is lowered in the usual manner to receive a fresh charge of molten lead. The dross or other impurities that may have been contained in the residual slug of the preceding charge, having been released by the remelting of the residual slug as described above, are now free to rise to the top of the fresh charge before the extruding operation is resumed. Thus the lead at the junction of successlve charges is free of impurities so that substantially perfect unions between successive charges are obtained.

It is to be understood, of course, that the extruding plunger is permitted to cool sumciently before the extruding operation is resumed, and the cooling thereof may be expedited, ii necessary, in any well known manner, such as by means of a cooling medium applied to the plunger either externally or internally.

What is claimed is:

In a cable sheath extruding press, an open cylinder for receiving molten metal, a plunger for extruding metal from said cylinder, said plunger being ada ted to be withdrawn from the cylinder to permit pouring a fresh charge of molten metal therein, and readily replaceable electrical heating means within the end of the plunger for fusing the surface of the preceding charge prior to withdrawal of the plunger.

JOHN WELLS. 

